"What's what?" demanded Hugh, peering in the direction Bob indicated.

"Look!" cried Bob.

"I am looking. What is it?" The tone of his friend's voice had alarmed him greatly, though he did not know what it was that Bob saw.

"Can't you see? Right down there!"

"Where? Where?" pleaded Hugh. "Tell me, Bob."

"Down under the track. I see sparks."

"It's a bomb," cried Hugh suddenly catching sight of the little flashes of light. "It's a bomb that man planted there."

"What shall we do?" cried Bob, acting as if he was ready to turn and run.

"Go and get it," said Hugh instantly. "Come along," and he started towards the spot of danger. Spurred on by his comrade's show of courage, Bob followed.

Their hearts were in their throats and terror held them in its grasp as they hurried along. The little sparks still appeared, and the sputtering of the fuse could be heard distinctly as they ran forward. The footing was dangerous and who could tell but that at any moment the bomb might explode and blow them into eternity.

Hugh reached the spot first. He was outwardly calm, but had the sun been shining his face would have shown white and frightened. A second later Bob arrived and stood beside him.

"There it is," he gasped. "It's a bomb all right."

"Pinch the fuse," cried Hugh excitedly. "Put it out."

Both boys reached for it, but Bob was first. He had completely recovered his nerve now and was perhaps even more self-possessed than Hugh.

Bob grasped the lighted part of the fuse between the thumb and forefinger of his right hand. He squeezed it tightly, but quickly withdrew his hand with a cry of pain. The fuse still sputtered.

"Let me!" almost sobbed Hugh. "Let me try."

He repeated Bob's performance, except that he held on in spite if the pain he suffered. With tight-shut lips and set jaw he pinched the fuse with all his strength. Finally he could stand it no longer and let go.

"It's out," cried Bob. "No, it isn't either," he exclaimed a second later as the fuse once more showed red and the tiny sparks again made their appearance. "We'd better run for it, Hugh. What's the use in our being blown up along with the bridge?"

"Get out of the way!" ordered Hugh, and Bob obeyed at once. There was something in the tone of his friend's voice that made him hasten to do as he said.

Hugh knelt on the ties and leaned down over the bomb.

"Here comes a train," cried Bob suddenly. "On this track too."

Hugh paid no attention to this warning. He picked the bomb up in his two hands and staggering under its weight, carried the spitting and sputtering engine of death to the edge of the bridge. With a supreme effort he hurled it from him. A moment later a splash told that it had landed in the river below.

"That'll never do any more harm," he gasped faintly.

"Stay there, Hugh!" shouted Bob. "Look out for the train!"

The two boys crowded close against the side of the bridge and a moment later a heavy train thundered past them. Through the lighted windows could be seen crowds of passengers, and Hugh and Bob shuddered as they thought what might have happened to the train with its load of precious human freight had the bomb exploded. They felt faint and weak after their experience and presently sat down until their shattered nerves should have recovered somewhat from the shock.

The night was cool, but Bob mopped his perspiring brow. "Whew," he gasped. "That was a close call."

"I should say it was," echoed Hugh. "What luck that you should have seen those sparks when you did! There was only a couple of inches of fuse left."

"Lucky you were with me too," said Bob soberly. "If I'd been alone I think I would have run for home."

"Haven't you two gone home yet?" demanded a voice, and the two boys looked up to see Harold standing over them.

"Not yet," said Bob.

"Well, you'd better skip," Harold advised. "You'll get in trouble around here."

"There'd been more trouble if we hadn't been here," said Bob quietly.

"What do you mean?"

Bob related the story of the bomb to his brother.

"Say!" exclaimed Harold in an awestruck voice. "That was pretty good work of you two. A train came along on that track too."

"Hugh got the bomb out just in time," said Bob.

"Say," repeated Harold. "Say," he said again, completely overcome.

"Do you think they'll let us enlist on the strength of what we did?" Hugh asked hopefully.

"I doubt it," said Harold. "I'll certainly speak to the captain about you though."

"We might as well go home now, I guess," said Bob. "You don't want to see your canoe tonight, do you?"

"No," replied Hugh grimly. "I've lost all interest in canoes for the present."

They said good night to Harold and started homeward. They still felt a little shaky as a result of the bomb episode, but before long the walk and the crisp night air had refreshed them and their spirits once more revived.

"I wonder what they'll do to that German," exclaimed Bob.

"Harold said they had locked him up for over night, and I guess when they hear what he tried to do, they'll keep him longer than that."

"They'll send him to jail probably."

"I hope so," said Hugh. "Any man who would try to blow up a bridge and kill crowds of people deserves worse than jail."

"They'll give him five or ten years all right," said Bob.

"Yes, and when they try his case we'll have to act as witnesses I suppose."

"I wouldn't mind that," Bob exclaimed. "It might be a lot of fun."

"Aren't these plotters silly?" said Hugh. "They may be able to blow up a plant or a bridge here and there, but they'll lose more than they gain."

"Why so?"

"Because it'll make the people mad. When they once get angry they'll fight and work much harder to defeat Germany. Half the people in this country don't seem to realize that we are at war now, but when a few of them get blown up we'll begin to do something."

They discussed the war and the possibility of sending American troops to France. Hugh wanted to go into the aviation corps when he was old enough but Bob thought the infantry and solid ground under his feet would be good enough for him.

Presently they came near home. Hugh lived two blocks farther down the street than Bob and consequently he had to pass the Cooks' house on his way.

"There's the Wernbergs'," said Bob. "A light in the second story back window, and two automobiles in front."

"Do you suppose they're up to anything?" exclaimed Hugh.

"I suspect them all right, but how can we prove it?"

"I have an idea," Hugh exclaimed suddenly. The two boys were standing on the opposite side of the street from the Wernbergs' house, regarding it curiously.

"What is it?"

"Can you get your automobile?"

"I guess so, if Heinrich hasn't taken the family out."

"Let's get it and follow one of those machines. In that way we can see where the people live who are at the Wernbergs'. Maybe we can learn something about them if we know who they are."

"A good scheme," exclaimed Bob readily. "We'll have to be awfully careful though; if they ever found out we were following them it might go hard with us."

"We'll be careful all right," said Hugh grimly. "Come ahead, we want to be ready to start and they may leave at any time."

The two boys walked quickly up the street, taking care to keep on the opposite side from the Wernberg home. When they arrived in front of the Cooks' they darted across the street and hurried along the driveway until they came to the garage. The door was shut and locked. Bob knocked loudly.

There was no reply. Bob looked at his watch under the light of a match which Hugh struck. It was twenty minutes of eleven.

"That's queer," he muttered. "Heinie is usually in bed long before this."

"Maybe he is now, and is asleep," Hugh suggested.

Bob glanced up at the second story window. "I don't think so," he said. "The window is closed in the room where he usually sleeps, and I know he is a crank on fresh air."

"Throw some gravel at it," said Hugh. "That'll get him up if he's there."

This plan was followed, but with no success.

"He's out," said Bob finally. "What'll we do?"

"Is the car there?"

"Yes, but what good will it do us if we can't get in?"

"Haven't you got a key to the garage up at the house?"

"Father has one, but I don't dare wake him now." Bob glanced at the house and the absence of lights on the first and second floors convinced him that his family were all in bed. A single light shone from a window on the third floor where Lena, the cook, slept.

"Maybe we can force a window," suggested Hugh. "You can open the door from the inside, can't you?"

"Oh, yes," said Bob. "Let's try a window anyway."

They went around the corner of the garage and the first window they tried yielded immediately. A moment later both boys had clambered inside, and presently Bob found the electric light button. As the light flooded the garage Heinrich's angora cat rose sleepily from the tonneau of the automobile and stretched himself. A cloth covering over the parrot's cage kept that garrulous bird quiet. Percy lay stretched out in the water which filled his tub.

"The dog must be out with Heinrich," said Bob.

He seated himself in the driver's seat of the car, and Hugh lifted the drowsy cat to the floor. Bob pushed a button, put his foot on the self-starter and the engine started. Heinrich always backed the car into the garage so that it was headed in the right direction as it stood. Hugh undid the spring catch on the door and rolled the door back. They were now ready to start.

"I'll go down by the street and watch the Wernbergs," said Hugh. "I hope they haven't gotten away while we have been fooling around here."

"I guess not," said Bob. "When they start you whistle twice and I'll be with you right away."

"All right," agreed Hugh. "You'd better run with your lights dimmed."

"I shall, don't worry."

Hugh hurried away. Bob was left alone in the car and he presently shut off the engine. He had wished to warm up the motor so that it would start readily when the time came; he was convinced that it would do so now.

He thought over the events of the day, and for the first time he realized that he was tired. Excitement had spurred him on and the intense interest he took in the war had made him forget all else. He wondered if he and Hugh were starting off on a wild goose chase now. What particular reason had they to suspect the Wernbergs anyway? True, all Germans were more or less under suspicion just then, but why the Wernbergs any more than the others? He recalled his fight with Frank that morning, and his father's remarks. Perhaps it was just as well to go out that night after all.

Bob thought of the war and the terrible things the Germans had done. What brutes and beasts they were! The Germans had been busy in the United States too. The big factory at Eddystone had been blown up that day, with the loss of a hundred and twenty-five lives, mostly of girls. That showed what the American people had to guard against.

"I hate them all!" muttered Bob angrily. He took that back a moment later, however, as he thought of Heinrich. Surely their chauffeur was as faithful and kindly a soul as ever lived; his love for animals proved that. Then there was Lena, their cook, a buxom woman of forty who had never been heard to utter a cross word in her life.

Heinrich was capable of getting mad, however, particularly about the car. Bob wondered what he would say if he should arrive home now, and find him preparing to go out in it and perhaps get it dirty.

His reverie was suddenly interrupted by the sound of two whistles. A moment later the motor was purring softly, and with the headlights dimmed, the big sixty horse-power car slid out of the garage and started silently down the driveway.